A humectant amino acid used to attract water to the skin’s surface. It is a part of the skin's Natural Moisturizing Factor, a mixture of various compounds that keeps the skin’s surface well hydrated. Arginine can also be used as a pH adjuster.
All functions


Arginine is a partially essential amino acid. Amino acids are important building blocks of all proteins.

Arginine is usually added as a humectant moisturizing ingredient in skincare products. The amino acid retains water to the skin’s surface and is also a part of the so-called Natural Moisturizing Factor (NMF), a complex mixture of free amino acids and other water-soluble compounds found in skin cells.

Arginine can also be used as a pH adjuster because it is slightly alkaline. Contrary to popular belief, arginine and other amino acids don't function as ‘skin nutrition’ and do not help with the synthesis of collagen or elastin. This is due to the simple fact that they are water-soluble and cannot pass through the skin barrier.

All of the effects of arginine, therefore, happen on the surface of the skin.


Ahsan H. (2019). Immunopharmacology and immunopathology of peptides and proteins in personal products. Journal of immunoassay & immunochemistry, 40(4), 439–447.
Oshimura, E., & Sakamoto, K. (2017). Amino Acids, Peptides, and Proteins. Cosmetic Science and Technology, 285–303.